Efforts to improve PV devices, particularly those devices that are integrated into building structures (e.g. roofing shingles or exterior wall coverings), to be used successfully, should satisfy a number of criteria. The PV device should be durable (e.g. long lasting, sealed against moisture and other environmental conditions) and protected from mechanical abuse over the desired lifetime of the product, preferably at least 10 years, more preferably at least 25 years. The device should be easily installed (e.g. installation similar to conventional roofing shingles or exterior wall coverings) or replaced (e.g. if damaged). It may be desirable to choose materials and components, along with design features that aid in meeting the desired durability requirements such as being free of deformations that would impair performance (for example as published in United Laboratories UL 1703 Standard—ISBN 0-7629-0760-6 and or Temperature Cycling Test pursuant to IEC16646).
To make this full package desirable to the consumer, and to gain wide acceptance in the marketplace, the system should be inexpensive to build and install. This may help facilitate lower generated cost of energy, making PV technology more competitive relative to other means of generating electricity.
Existing art systems for PV devices may allow for the device to be directly mounted to the building structure or they may fasten the devices to battens, channels or “rails” (“stand-offs)) above the building exterior (e.g. roof deck or exterior cladding). These systems may be complicated, typically do not install like conventional cladding materials (e.g. roofing shingles or siding) and, as a consequence, may be expensive to install. Also, they may not be visually appealing as they do not look like conventional building materials. “Stand-offs” to mount PV device every 2-4 feet may be required. Thus, installation cost can be as much or more as the cost of the article. They also may suffer from issues related to environmental conditions such as warping, fading and degradation of its physical properties.
Among the literature that can pertain to this technology include the following patent documents: US20080190047(A1); U.S. Pat. Nos. 4,321,416; 5,575,861; 5,437,735; 5,990,414; 6,840,799; EP1744372; U.S. Pat. Nos. 6,875,914; 5,590,495; 5,986,203; US2008/0115822; EP1923920; U.S. Pat. No. 7,365,266; US20070295393 A1; US20070295392 A1; WO 2008/139102; WO 2009/137348; WO 2009/137347; WO 2009/137352; WO 2009/137353; and U.S. Provisional 61/233,527, all incorporated herein by reference for all purposes.